update server/src/main/resources/static/js/lazyload.js.

移除全局index变量，防止变量污染引发问题

Signed-off-by: Frank Cheung <frank.cheung.work@outlook.com>

server/src/main/resources/static/js/lazyload.js

@@ -6,9 +6,10 @@ function isInSight(el) {
     return bound.top <= clientHeight + 100;
 }
 
-var index = 0;
+
 
 function checkImgs() {
+    var index = 0;
     var imgs = document.querySelectorAll('.my-photo');
     for (var i = index; i < imgs.length; i++) {
         if (isInSight(imgs[i])) {